Description

I suggest to introduce concept of decoders as functionality that works
independently from rendering functionality. JSF already has dedicated Renderer
class. So it makes sense to do the same thing for decoding functionality.
The first benefit from this approach would be possibility to send data from
client directly to decoder, skipping on the way to it necessity to use JSF
components and JSF life cycle. JSF developers will be able to create more
stateless JSF applications and use Javascript libraries in more flexible than
now manner.

Note: The first argument of the method "post" would be optional and called "url".
In case if developer need to customize handling of data from client we will use
this argument as way to identify decoder that will handle the data.